The present invention relates generally to the field of grasping, transporting and palletizing objects such containers for packaged goods and specifically to a device that is capable of loading and palletizing empty, partially filled or completely filled open-topped or unsealed containers. Open-topped or unsealed containers, and especially those that are empty or partially filled, are difficult to pick up, hold and transport, due to their relatively thin flexible walls and lack of structural integrity.
At the end of a conveyor line, manufactured products often arrive packaged in containers. While the container serves the primary purpose of protecting the product during shipping, the container may also serve the function of identifying the product. On more elaborately printed containers, there may appear indicia advertising the product, its benefits or its application. This latter type of packaging design is commonly found on products sold at the retail store level. Therefore the container must be aesthetically attractive and visually appealing. Accordingly, it is of utmost importance that each container, and especially its product indicia, not be damaged during removal from the assembly line and palletizing for shipment.
In most instances the task of removing the container from the conveyor line and palletizing the containers for shipping has been carried out manually. While having some advantages, such as insuring that the container is not damaged, manually handling containers is relatively a strenuous and tedious task. The continued lifting and moving of multiple containers can cause workers to strain and injure their backs. Further, depending upon the output speed and configuration of the conveyor line, many workers may be required to remove and properly palletize the containers. In an effort to reduce workforce size and injury costs, there has been a significant move toward automating this process by utilizing robots. As is known in the art, industrial robots may be fitted with various grasping devices, known as "end-effectors", for picking up and moving objects, including containers.
Most product containers are rectangular in shape and include four side walls, a bottom wall, and a top wall. Provided that the container has been properly sealed, the container is likely to have sufficient structural integrity allowing it to be grasped in a number of manners from the assembly line by a robotic end-effector and transported to a pallet. For example, the container may be removed from the assembly line by one or more suction cups that temporarily adhere to the top wall of the container. Alternatively, a pair of arms may apply a small amount of pressure to opposing side walls of the container such that the container may be lifted and transported.
However, if the container to be transported from the assembly line to the pallet lacks a top wall or if the container is not sealed, its structural integrity is greatly diminished. Suction cups cannot be attached to a container lacking a top wall. If a pair of arms were employed to apply a sufficient amount of pressure against opposing side walls of an open-topped or unsealed container, the container would most likely collapse or crush before the exerted force was great enough to lift and transport the container.
Another factor that controls the choice of device employed for palletizing containers is the consistency of container size. If each container coming off the conveyor line has the same physical size, the robotic end-effector can be designed specifically for that specific container size. However, if the container size varies, the end-effector must be capable of adjusting its grasping mechanism to accommodate the various container sizes.
A third factor that often dictates the means of removing containers from conveyor lines and transporting them to pallets is the amount of space available at the end of the conveyor line for this operation. Often times there is very little space allocated at the end of the conveyor line for palletizing containers. If a robotic end-effector is to be utilized, it must be sufficiently compact to allow for installation and operation within the allotted space available for such a device.
Accordingly, there is a need for a device that may be used for the removal and transportation of open-topped or unsealed containers. There is also a need for a device capable of easily grasping and palletizing containers of various sizes on the same pallet. More specifically, there is a need for a device that is compact enough to be positionable and operationable at the end of an conveyor line and that can pick up open-topped or unsealed containers of various sizes and transport those containers to pallets. Furthermore, the device must be able to properly palletize the containers to insure stability of the pallet during shipment.